Fluorescent in situ hybridization analysis of chromosomally normal gametes and abnormal arrested embryos.

OBJECTIVE

The purpose of the present study was to investigate if the arrested embryos from a couple with several previously failed IVF treatments were chromosomally normal. Probes for chromosomes X, Y and 18 were used.

RESULTS

A couple had undergone 7 in vitro fertilization treatments over a 2 1/2-year period without achieving a pregnancy. In each cycle, where fertilization was obtained, the development of the embryos was arrested. Fluorescent in situ hybridization probes for chromosomes X and Y (and 18) was carried out on gametes and on embryos in 2 separate cycles. Sperm and oocytes were normally haploid X0 or Y0. The nuclei of the blastomeres were fragmented and mosaic for X or Y, or monosomic X0, despite the fact that 2 pronuclei had been assessed on day 1 following intracytoplasmic sperm injection.

CONCLUSION

Chromosomally normal gametes can result in abnormal embryos manifested by arrested development and unexplained infertility.